A spokeswoman from the company today said 30 per cent of the VPS servers affected are now back online.

"Unfortunately, there have been a small number of incidences where we may not be able to restore a customer’s data. We will continue work to do so and we are in contact with every affected customer to keep them informed on the situation," she said.

"While working on this issue is our current priority, we have also put a series of measures in place to ensure that this does not happen again in the future."

He added: "We fully understand that this is the worst possible outcome. In order to help speed the process of getting you back online, we strongly advise that you attempt to restore from personal backups."

In its latest twitter update yesterday, 123-reg said: "As more and more sites get back online emails are being sent directly to customers as more site become live on a case-by-case basis."

However, Winslow expressed sympathy to the customers still unable to access their sites: “We understand how business critical a website is to you and we have been doing everything in our power since the fault occurred to get you back online. We would like to extend our apologies to you for this.”

The company is currently working with data recovery biz Kroll Ontrack to get back on its feet.

One customer, Lawrence Turner, said: "I was offered 6 months free hosting too (even though they still took payment), but that's of little use to me now as I've already migrated everything over to AWS."

Another customer still unable to access his website said: "There's no way I am going to continue using them, so I will be pursuing them for a financial remedy."

The 123-reg spokeswoman added: "We understand the potential impact of this fault on all our customers and this is something we take extremely seriously." ®